Batch adsorption experiments were carried out to remove reactive black 8 (RB8) from their aqueous solutions using zinc oxide nanoparticles (ZnONPs). The various affecting parameters such as solution pH, contact time, initial dye concentration, and sorbent dosage on the removal efficiency were studied. The equilibrium adsorption data of RB8 on ZnONPs surface were analyzed by Langmuir and Freundlich isotherms. The adsorption process correlated with Langmuir model better than Freundlich isotherm and the maximum adsorption capacity was found to be 27.6 mg g⁻¹. The experimental results showed that the pseudo-second-order kinetic equation could best describe the sorption kinetics.